Elliptic iris.



F.'.vGARBuTT-. EL-LlPnc mls. APPLICATION FILED JULY I5, I'SIB.

Patented Apr. 29,1919.

FRANK E. GABBUTT, OF LOS ANGELES, CALIFORNIA.

ELLIPTIC IRIS.

To a-VZZ whom it may concern Be it known that I, FRANK E. GAnBUTT, a citizen of the United States, residing at Los Angeles, in the county of Los Angelesl and State of California, have invented a new and useful Elliptic Iris, of which the following is a specification.

My invention relates to the ant of photography, being more particularly an iris for use on motion picture cameras by means of which the field of the camera is elliptical in shape, the size of the opening in the iris being regulated at the will of the operator. I

am aware that iris'diaphragms have beenV used on cameras in which the iris constituted a circle, but by the use of an iris having an elliptical openingtherein a muchmore -artistic eiect can be obtained, particularly where there are one or two subjects, one or more of which would be entirely cut out by vusing an iris circular inshape. Y

The principal object of my invention is to produce an iris of simple form and construction in' which the openingis elliptic in shape and the provision of simple means for the operation of the same.

Referring to th drawings, which are for illustrative purposes only.

Figure'l isa face View of an iris em` bodying a form of my invention, a portion of the same being broken away to better show the form of the leaves.

Fig. 2is a .vertical sectional view on line 2 2, Fig 1. Y y

The device consists of a stationary ring 10, to the outer edge of which is secured by means of suitable pins 11 a circular band or flange 12 which extends above the face of the stationary ring. Su rimposed upon each other on the face of t e stationary ring is a series of leaves'f13, each leaf being pivotally mounted on a pin 14 supporteclin a rotatable ring 15, which rotates on the inner face of the circular band 12, being retained therein by a retaining ring 16 threaded into the circular band 12, and having a flange 17 which extends over the edge .of the circular band 12, as shownl in Fig. 1 2.

Each of the leaveaalso is provided with a stud 18 whichlextends into a c'urved cam slot 19 formed in the face 4'of the, stationary 'ring 10, it being understood that there is. a

separate curved slot 19' for each stud 18. The leaves 13 `are formed with a curved Specication of Letters Patent.

Application led July 15, 1918. Serial No. 245,111.

Patented Apnea, 1919.

of the leaves -being a developed curve and different from each other with the exception that the leaves on one half of the iris have each atcorrespondinglyshaped leaf on the opposite half of the iris, the pivotal points of each pair of leaves having the same shaped inner edge, being directly opposite to each other.

-The stationary ring 10 is provided with a central opening 22 which is elliptical in shape, the longest axis of such opening being of the same diameter as a circular opening 23 formed in the rotatable ring 15. The circular band l2 is provided with a slot 25 through which extends an operating arm or pin 26, the inner end of such arm extending into the rotatable ring 15, as shown in Fig.

The size of the iris is determined by the position of the rotatable ring 15 with relation to the stationary ring and the moveinent of the rotatable ring by meansA of the operating arm 26 causes the respective leaves to be swung inwardly or outwardly according to the direction of movement of the operating arm due to the fact that the studs -on the respective leaves are guided by their respectiveslots, thereby causing the leaves to swing inwardly o-r outwardly according to the direction of moyement of the rotatable ring. The slots 19 are curved in shape, be-

pin on each leaf extending into the rotatable ring to pivotally mount its associated leaf on the rotatable ring, each of said leaves'having a curved inner edge, the curvature of the inner ed' of the leaves in each pair being substantially identical and different from the curvature of the inner edge of the other' leaves, said rotatable ring having a series of. curved slots therein, one foreach leaf, the slots for each pair of like leaves being identical and such slots being eccentric to the center of the iris, a stud on each leaf extending into one of the slots, and means for 'ing eccentric to the center of the iris and Cmoving the rotatable ring to vary the position of the leaves. 'f

2. An elliptic iris diaphragm 'consisting of a stationary ring, a rotatable ring, a plu` rality of pairs of leaves interposed between said rings, each leaf being pivotally mounted independent of each other on the rotatable ring, the leaves in each pair being` substantially4 identical in outline butdierent from the outline of' all the other leaves, said stationary ring having cam slots therein eccentrically arranged with respect to the center of the iris, a stud on each leaf extending 1n`to one of the cam slots -in the stationary ring, and means for operating' the rotatable 3. `An elliptic iris diaphragm consisting of a stationary ring,a rotatable ring, a plurality of rings, each leaf being pivotally mounted independent of all the other leaves on one of said-rings, and means whereby the leaves pairs of leaves interposed. between said are s'o connected to the stationary ring that;

the rotation of the rotatable ring will simultaneously move all the leaves, the leaves in each pair being substantially identical inoutline but different from the outline of all the other leaves. 4

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 3rd day of July,'l918.

FRANK E. GARBUTT.' 

